Suction accumulator



2 Sheets-Sheet l E. P. KELLIE SUCTION ACCUMULATOR Feb. 27, 1968 FiledJan.

Ehm/MW' E. F. KELLIE Feb. 27, 1968 S UGT ION ACCUMULATOR 2 Sheets-Sheet2 Filed Jan. e, 1966 lAlfl l III. xlllllll United States Patent3,370,440 SUCTION ACCUMULATOR Edward P. Kellie, Detroit, Mich., assignorto AC & R

Components, Incorporated, Chicago, lll., a corporation of Illinois FiledJan. 6, 1966, Ser. No. 519,114 9 Claims. (Cl. 62-503) ABSTRACT F THEDISCLOSURE A suction line accumulator adapted to prevent liquid slugs ofrefrigerant and/ or lubricant from passing into the compressor, togetherwith means in said accum-ulator for atomizing accumulated liquidrefrigerant and/ or lubricant and directing the atomized liquids fromthe accumulator.

The present invention relates to suction accumulators for use inrefrigeration systems, heat pump systems and the like. Theseaccumulators are usually installed in the suction line side of thesystem between the evaporator and the compressor, and are intendedprimarily to prevent slugs of refrigerant in liquid form from passinginto the compressor. The entry of such slugs of liquified refrigerantinto the compressor can cause serious damage to the valves, piston,bearings, etc., of the compressor.

Heretofore, the majority of prior accumulators used in such situationsmerely functioned as sumps in which slugs of liquied refrigerant.together with lubricating oil, accumulated. The liquid refrigerantremained in such sump until conditions prevailed which would permit theliquid refrigerant to evaporate within the accumulator, so that it couldthen be drawn off as a gas or vapor to the outlet connection leading tothe compressor.

However, the lubricating oil will not ordinarily evaporate at thetemperatures which vaporize the liquied refrigerant, and hence the oilwill become separated or distilled out of the liquified refrigerant andwill eventually load up the accumulator with oil, and will reduce theoil level in the crank case of the compressor to a dangerously lowlevel. Prior attempts to suck or drain oil out of the sump havegenerally resulted in slugs of oil in liquid form and (under someoperating conditions) slugs of liquid refrigerant being returned to thecompressor with consequent damage to the latter.

The general object of the invention is to avoid the above difficulties,which I have accomplished by providing in the upper portion of the.accumulator adjacent the outlet, leading toward the compressor,atomizing means in the form of a venturi type of jet through which thegaseous refrigerant ows lat an accelerated velocity for creating areduced pressure in an atomizing zone at the outlet portion of theventuri jet. A dip tube extends from the lower portion of the sump upinto the atomizing zone, so that the reduced pressure in this atomizingzone will draw oil and liquid refrigerant up through the dip tube foreffective atomization in this atomizing zone. From this zone theatomized refrigerant and oil travels to the compressor in a vaporouscondition where it can be compressed without the possibility of injuryto the compressor.

The normal flow of gaseous refrigerant through the venturi type of jetcauses an acceleration of velocity, and as this gaseous refrigerantpasses'out of the venturi jet it reexpands and creates la zone of lowerpressure. This zone of lower pressure functions as an atomizing zone inwhich liquitied refrigerant and oil are atomized substantially into avaporous condition.

In attaining the above principal object, I have provided structuralmeans which is simple and rugged and adaptable to a variety ofinstallations.

Mice

Other objects, features and advantages of the invention will appear fromthe following detailed description of preferred embodiments thereof, Inthe accompanying drawings illustrating such embodiments:

FIGURE l is a diagrammatic layout of a typical refrigeration systemutilizing the improved suction accumulator.

FIGURE 2 is a fragmentary longitudinal sectional view through theaccumulator.

FIGURE 3 is a fragmentary sectional View of the venturi jet portion ofthe accumulator, illustrated on a substantially larger scale.

FIGURE 4 is a view similar to FIGURE 2 but illustrating a modified formof venturi jet apparatus;

FIGURE 5 is a perspective view of this modified venturi jet, removedfrom the accumulator; and

FIGURE 6 is a transverse sectional view of another embodiment having adifferent form and arrangement of dip tube.

The conventional refrigeration system shown in FIG- URE 1 comprises thecompressor lil, the discharge line 11 leading therefrom to the condensor12 and thence from the condensor 12 to the liquid receiver 14. From thereceiver 14 the liquiiied refrigerant is conducted through line 15 tothe metering device or expansion valve 16. From valve 16 the refrigerantows through the evaporator 17 to perform its cooling function and thenceows through the suction line 18. 18 back to the compressor 10. Theimproved suction accumulator 20 is interposed in this suction line 18,18' and it can be located at practically any desired point in the line,the only requirement being that the accumulator be disposed so that theinlet and outlet and venturi jet are in the upper part of the shell 21.FIGURE l illustrates the accumulator as being installed substantiallyabove the line of the suction valve on the compressor, but, as abovestated, it is to be understood that the accumulator can be otherwiseinstalled, such as in the line of the suction valve, or below such line,if desired. In any of these locations, the refrigerant ows from theevaporator 17 through suction tube 18 to the inlet of the accumulator 20and thence flows from the outlet of the accumulator through extensionsuction tube 18 to the inlet of the compressor 10.

Referring now to the construction of the improved accumulator, it willbe seen from FIGURES 2 and 3 that it comprises a cylindrical metallicshell 21, preferably composed of steel and disposed horizontally. Whileshell 21 is shown as relatively long and narrow, its length and diametermay be varied without departing from the scope of my invention. Theopposite ends of the shell 21 are provided with inlet and outlet endheads 22 and 23. These end heads are formed with inwardly turned flanges24 and 25, respectively, which fit snugly over the ends of theaccumulator shell and are welded thereto at 26 and 27.

The inlet head 22 is formed with an eccentrically located inlet port 28,and the outlet head 23 is formed with a similar eccentricallylocatedoutlet port 29, both of which ports have outwardly projectingcylindrical flanges 28' and 29', respectively. These inlet and outletend heads are assembled over the ends of the accumulator shell withtheir inlet and outlet ports 28 and 29 in axial alignment, and disposedat a relatively high level on the accumulator shell. All of theaccumulator space lying below such inlet and outlet ports constitutes asump 36 for the accumulation of slugs of liquid refrigerant, oil, etc.

Mounted withinV the inlet port 28 to extend outwardly therefrom is acylindrical extension sleeve 32, which has its inner end brazed orotherwise fastened to the end head 22, as indicated at 34. Mounted overthe protruding end of this extension sleeve is a copper coupling sleeve36 which is brazed at 37 to the extension sleeve,

3 The suction line 18 leading from the evaporator 17 has a sweat iitwithin the coupling sleeve 36. If desired, the inlet port can be locatedin the top of shell 21 in a known manner and the left end of the shellwill then be closed -by a head or cap.

Referring now to the outlet end of the accumulator, it will be seen thatthe outlet port 29 has an extension sleeve 41 which is welded or Ibrazedto the end head at 42. This latter extension sleeve also has aprotruding end to which is brazed a coupling sleeve 44. The extending orcontinuing part 18' of the suction line 18 has a sweat lit within thiscoupling sleeve 44. The extension sleeve 41 in this instance issubstantially longer than the extension sleeve 32, and has its inner endprojecting into the accumulator shell. Mounted in this inwardlyprojecting end is the venturi jet 50 which aids in performing theaforementioned atomizing action. This venturi jet comprises a length oftubing which is cylindrical in its inner end, and has a reducing taper52 leading outwardly to its outer end. This constricting taper createsan atomizing zone Z which surrounds the venturi taper and also extendsaxially therefrom. The velocity through this atomizing zone isaccelerated; and, moreover, the pressure in this atomizing zone is alsoreduced. The reduced pressure extends back int'o the tapering space 54formed between the cylindrical inner wall of the sleeve 41 and theconical outer surface of the venturi jet.

Extending from the atomizing zone Z downwardly adjacent to the bottom ofthe sump is a substantially vertical dip tube 60. This dip or atomizingtube 60 extends upwardly through a hole 62 in the extension sleeve 41,in which hole the tube is fastened. The upper extremity of the tubeterminates in cl'ose proximity to the discharge edge of the atomizingjet, and the tube is preferably disposed with its longitudinal axisextending substantially flush with this discharge edge of the atomizingjet. The lower end of the atomizing tube has a beveled entrance opening64 disposed in close proximity to the bottom of the sump.

In the operation of the accumulator, all of the refrigerant comingVthrough the suction line 18 in a gaseous state passes directly throughthe upper portion of the accumulator from the inlet port 28 to theoutlet port 29, and thence through suction line 18 to the compressor. Onthe other hand, such portion of the refrigerant as is in the formfofliquiiied slugs is precipitated out of the ow of refrigerant down intothe sump. However, so long as the system is in operation with somegaseous refrigerant flowing therethrough, the venturi jet is exerting anaspirating action on the liquid refrigerant and oil in the sump, drawingthe same upwardly through tube 60 to be atomized by the venturi jet.Thus, there is practically no possibility of slugs of liquid refrigerantbeing carried over into i the compressor.

The modification illustrated in FIGURES 4 and 5 is substantiallyidentical to the above-described embodiment, except at the intake end ofthe venturi jet tube 50. Here, there is fastened a deflector tube 70having a flanged deilector cap 71. The tube 70, which is mainlycylindrical, has its upper periphery slotted or cut away longitudinallyso that there is formed an upper longitudinal slot 72 therein.

In the operation of this modified venturi jet gaseous refrigerant entersthe venturi jet tube 50 through slot 72 in the top 'of the tube 70 andcauses an atomizing function as described in connection with FIGURES 2and 3. Deflector tube 76 and its cap 71 deflect entering surges ofliquilied refrigerant so that it will not ow into the end of the venturijet tube 50, and then pass over to the compressor. Liquified refrigerantmust rise to the top 'edges 75 of the slot 72 before it can spill overand enter tube 50.

In FIGURE 6, I have shown a modied form of dip tube 76 having itsdischarge end 77 opening into the upper :portion of the extension sleeve41. A sweeping curve' 78 joins this discharge end with the lowerstraight inlet end 80. thereby avoiding any sharp angular bends in whichblockage or restriction might occur. The discharge end 77 is preferablylocated in the atomizing zone Z, substantially in the same transverseplane with the outlet end of the venturi jet 50. This curved form of diptube 76, with its higher point of discharge 77, is exemplary of othershapes that the Adip tu-be might take, either for the embodiment shownin FIGURE 3 or for the embodimeut shown in FIGURE 4.

While I have illustrated and described what I regard to be the preferredembodiments of the invention, it will be understood that such are merelyexemplary, and that numerous modifications and rearrangements may bemade therein without departing from the essence of the invention. v

I claim:

1. In a suction accumulator for a system of Vthe class described whichincludes a compressor housing and an evaporator, the combination of anaccumulator chamber which is adapted to be disposed in the suction linebetween the outlet of the evaporator and the compressor housing, portmeans permitting passage of gas and vapor into and out of said chamber,a sump in said chamber for collection of liquids entering theaccumulator chamber, and atomizing means in said chamber adapted toatomize collected liquids and direct the from the cham-ber, saidatomizing means comprising a venturi jet having a tapering discharge endpositioned to provide an area of low pressure, and a dip tube whichextends upwardly from said sump and has its upper end at said area oflow pressure outside of and adjacent to saiddischarge end,- wherebyliquid is drawn up the dip tube by the venturi jet and projected in anatomized condition into the stream of gas and vapor flowing from saidchamber.

2. The combination of claim 1 wherein said port means Y comprises inletand outlet ports, and said mounted directly in said outlet port.

3. The combination of claim 1 wherein the port means comprises inlet andoutlet ports, and wherein a tubular member is disposed in said outletport and supports the atomizing means.

4. The combination of claim 1 wherein said accumula venturi jetis tor isdisposed substantially horizontally, with said port opposite ends ofsaid chamber, and liquidy deflecting means at said outlet port.

7. The combination of claim 1 wherein said port meansl comprises aninlet port and anoutlet port disposed inI the upper portion'of said`chamber above said sump.

8; The combination of claim 1 wherein said port means comprises inletand outlet ports disposed at different parts of said chamber, andwherein liquid deflecting means is disposed at said outlet port.

9. The combination of claim 1 wherein the dip tube has its lower end insaid sump and Vextends upwardly in a sweeping curve to a discharge enddischarging downwardly adjacent said venturi jet.

References Cited UNITED STATES PATENTS 1,951,915 3/1934 Kagi 62-47l2,121,253 6/1938 McGuffey 62-503 X 3,180,567 4/1965 Quiggle 62-503 XMEYER PERLIN, Primary Examiner.

